(1) Field of the Invention
The invention concerns a pump with an integral electronically commutated, direct-current motor with an inner, permanent-magnetic rotor disposed in a wet chamber, which forms a compact structural pump-rotor unit with a turbine pump wheel, a claw-pole plate made of a soft magnetic material disposed in a dry chamber or dry space, a ring-shaped winding, and a soft magnetic, return or back-iron ring mounted on the claw-pole plate and disposed around the winding, including a claw-pole stator and a can like partition wall that acts as a containment shell to separate the dry chamber from the wet chamber or wet space.
(2) Description of Related Art Including Information Under 37 CFR 1.974 and 1.98
Such a pump is known from German patent DE 10 2006 021 246 A1, which is provided with a claw-pole stator consisting of two claw-pole plates with paraxial claws gripping one another, forming opposing poles. Because the claw-pole plates are each made of a single, soft magnetic plate, the stator turns out to be in saturation, primarily in the area of the axial stator ends with higher voltage applied at the winding, whereby the performance of the pump is limited. Claw-pole stators are distinguished by simple fabrication, low weight, and sturdiness. Hence, in many cases, it excludes the use of armature stators, with a plurality of single-pole windings and a plated stator set, in particular in use as a supplementary water pump in a vehicle.